1. Field of the Invention
The present invention relates to an exercise machine having an oval-shaped mechanism, and more particularly to an oval-shaped mechanism having driving arms, which can provide a longer and varied stroke with respect to the fly wheel.
2. Description of the Related Art
Currently, a prior art exercise machine, as shown in FIG. 11, comprises: an oval-shaped structure 50, two swing handles 60 and two slidable bars 70. The oval-shaped structure 50 comprises a base 51 having a fly wheel 52, and a standing rod 53 is attached to a front end of the oval-shaped structure 50. The fly wheel 52 has a shaft 521 extending from two sides of the flywheel 52. A pivoting shaft 531 extends from two sides of the standing rod 53. The two swing handles 60 respectively have a gripping portion 61, a linking arm 62 and a connecting tube 63 jacketed onto the pivoting shaft 531 of the standing rod 53. The linking arm 62 has an assembly portion 64 at an opposite end of the gripping portion 61. The slidable bars 70 each have a first pivoting portion 71 for attachment onto the assembly portion 64 of the respective swing handle 60, a second pivoting portion 72 with a ring for jacketing onto the shaft 521 of the fly wheel 52, and a pedal 73 disposed on a predetermined position of each slidable bar 70. When a user wants to operate the exercise machine, he or she needs to stand on both of the pedals 73 of the slidable bars 70 and hold both of the swing handles 60. By swinging both arms and stepping both legs, the fly wheel 52 provides continuous movement and identical travel strokes for the swing handles 60 and the slidable bars 70.
However, the prior art exercise machine has following drawback: since second pivoting portion 72 with a ring is directly jacketed onto the shaft 521 of the fly wheel 52 and the first pivoting portion 71 is attached onto the assembling portion 64 of the swing handle 60, the oval-shaped structure 50 has a travel stroke limited by the fly wheel 52 such that slidable bars 70 and the swing handles 60 have the same travel stroke as the fly wheel 52.
Therefore, it is desirable to provide an exercise machine to mitigate and/or obviate the aforementioned problems.